Compostable material for packaging

Abstract

A compostable material and methods of forming the same are described. The compostable material includes about 90% to about 99% by weight of a compostable polymeric material and a nucleating agent. The compostable material has a degree of crystallinity of about 5% to about 45%.

1 . A compostable material comprising:
 about 90% to about 99% by weight of a compostable polymeric material; and   a nucleating agent,   wherein the compostable material has a degree of crystallinity of about 5% to about 45%.   
     
     
         2 . The compostable material of  claim 1 , wherein one or more crystalline regions of the compostable material comprise a plurality of spherulite structures. 
     
     
         3 . The compostable material of  claim 1 , wherein the compostable material is translucent or transparent. 
     
     
         4 . The compostable material of  claim 1 , wherein the compostable polymeric material is selected from a group consisting of polylactic acid (PLA), polyhydroxyalkanoate (PHA), polybutylene succinate, cellulose, and combinations thereof. 
     
     
         5 . The compostable material of  claim 1 , wherein the nucleating agent is selected from a group consisting of ethylene bis-stearamide, an aromatic sulfonate derivative, a talc, and combinations thereof. 
     
     
         6 . The compostable material of  claim 1 , wherein the weight ratio of the compostable polymeric material to the nucleating agent in the compostable material is between 15:1 and 50:1. 
     
     
         7 . The compostable material of  claim 1 , wherein the compostable material comprises about 1% to about 10% by weight of the nucleating agent. 
     
     
         8 . The compostable material of  claim 1 , wherein the compostable material has a degree of crystallinity of about 15% to about 25%. 
     
     
         9 . The compostable material of  claim 1 , wherein the compostable material is substantially free of impact modifier. 
     
     
         10 . The compostable material of  claim 1 , wherein the compostable material is a microwavable material. 
     
     
         11 . The compostable material of  claim 10 , wherein the microwavable material is configured to retain its shape when exposed to a temperature of about 200° F. to about 250° F. 
     
     
         12 . A method of forming a compostable material, comprising:
 combining a compostable polymeric material and a nucleating agent to form a mixture, wherein the mixture comprises about 90% to about 99% by weight of the compostable polymeric material;   melting the mixture;   extruding the molten mixture into an extrudate; and   cooling the extrudate at a predetermined cooling rate to form the compostable material, the predetermined cooling rate being faster than a rate at which the extrudate cools when subjected to room temperature conditions;   wherein the compostable material has a degree of crystallinity of about 5% to about 45%.   
     
     
         13 . The method of  claim 12 , wherein the compostable material is a sheet. 
     
     
         14 . The method of  claim 12 , wherein the compostable material is a tray. 
     
     
         15 . The method of  claim 12 , further comprising thermoforming the extrudate to form the compostable material. 
     
     
         16 . A method of forming a compostable material, comprising:
 mixing a first compostable polymeric material and a nucleating agent to form a first mixture, the first compostable polymeric material having a degree of crystallinity of greater than 30%;   mixing the first mixture and a second compostable polymeric material to form a second mixture, the second compostable polymeric material having a degree of crystallinity of about 15% to about 45%;   melting the second mixture;   extruding the molten second mixture to form an extrudate; and   cooling the extrudate to form the compostable material;   wherein the compostable material has a degree of crystallinity of about 5% to about 30%.   
     
     
         17 . The method of  claim 16 , wherein the second compostable polymeric material has a degree of crystallinity of about 35% to about 45%. 
     
     
         18 . The method of  claim 16 , wherein the second compostable polymeric material has a degree of crystallinity that is greater than the degree of crystallinity of the first compostable polymeric material. 
     
     
         19 . The method of  claim 16 , wherein the second compostable polymeric material comprises the first compostable polymeric material and the nucleating agent. 
     
     
         20 . The method of  claim 16 , wherein the second compostable polymeric material comprises an extrudate, a thermoformed material, or combinations thereof.